1. Field of Invention
This invention relates to fluidic angular rate sensors and more particularly to improved temperature response in the sensing bridge thereof.
2. Description of the Prior Art
Of the fluidic angular rate sensors known in the art, perhaps the most widely used is the type illustrated in Schuemann U.S. Pat. No. 3,587,328, which comprises a self-contained unit including a piezoelectric diaphragm pump, and a fluid jet (or nozzle) through which a suitable fluid, such as an inert gas, is forced by the pump, thereby providing a charge or stream of gas directed toward a pair of temperature sensitive resistive elements which are differentially cooled by the jet whenever the jet is moved (such as in angular rotation) in a plane of sensitivity. The sensing elements are typically fine tungsten wires disposed on opposite sides of the center line of the nozzle boresight and perpendicular to the plane of sensitivity of the device. This device has found favor in many applications since it has no rotating parts, and substantially no moving parts (none except the vibrating diaphragm of the fluid pump).
Although fluidic angular rate sensors are theoretically capable of design for operation at a wide range of angular rates, it has been found that they are somewhat temperature dependent, particularly over the wide ambient required for military usage (typically, -65.degree. C. to +125.degree. C.).